1. Field of the Invention
This invention relates to a drainage plug to be used in a bathtub, a basin and the like.
2. Description of the Background and Pertinent Information
A prior art drainage plug is constructed such that a guide cylinder is fixed at a central part of a drainage port in a main body of the drainage plug, a supporting shaft is fitted within the guide cylinder in such a way that it may be moved up or down in the vertical direction, a plug cap for opening or closing the drainage port is arranged at the upper end of the supporting shaft and a thrust lock mechanism is installed within the guide cylinder.
The thrust lock mechanism may lock the supporting shaft at one end of a retracting path when the supporting shaft that is fitted in the guide cylinder is continuously advanced or retracted. This prior art drainage plug is constructed such that the guide cylinder has a thrust mechanism installed therein that is held at the central part in the drainage port with the end of the supporting shaft facing upward to the lock side. The plug cap is installed at the upper end of the supporting shaft.
Therefore, the plug cap is pulled up and locked to open the drainage port. When the lock is released, the plug cap may drop by its own weight to close the drainage port.
In order to move the plug cap up or down (for its opening or closing) in the drainage port, a chain or the like fixed to the upper surface of the plug cap is pulled up. However, a grasping and pulling up of the chain or the like every time the plug cap is to be opened or closed is a troublesome operation and fixing the chain or the like to the plug cap is quite troublesome.
A remotely operated system having no such chains as described above is disclosed in U.S. Pat. No. 4,596,057.
However, in such a remote controlled or operated system, it is necessary to provide accessory members such as a wire-like body, a guide tube and a connecting member or the like. It is also necessary to install these members and these requirements cause the system to be expensive.